A relationship that Theresa Neville struck up with a man who was three times her age when they met turned out to be deadly, a courtroom packed with her family learned Monday.

Jay Thomson, who was born in 1956, entered a surprise guilty plea to second degree murder on what was supposed to be the first day of a multi-week trial.

In the hour that followed his plea, the court heard some unusual details about the relationship he had with the woman he fatally stabbed 35 times June 17, 2013 while she sat on the living room couch of the Yates Road home they had shared for a year.

The 88-pound, 27 year old woman died from injuries to her head, face, back and hands, Crown counsel Mark Levitz told the court, while reading from a statement agreed to by defence lawyer Grant Gray.

Given the nature of these injuries, said Levitz, it’s clear she was killed in anger, while her two young children were downstairs.

Levitz said that Thomson was the father of these children.

Thomson had told RCMP that he met Neville at a Kelowna beach, around 2001, when she was 15 years old. At that time, he was 45-years-old and married to another woman who he remained with until a year before he killed Neville.

Neville had been crying that day on the beach, said Levitz, summarizing the statement from Thomson. The two spoke for awhile and then Thomson offered up his number, asking that Neville call him if she needed to talk. She did a few days later and the two struck up a friendship.

In the meetings that followed Thomson said that he helped her find God, and tried to break it off with her once that happened.

At that time, Neville wanted him to stay with her. To do so, he said, she asked him to teach her how to drive. He agreed and at some point after that she told him that she was in love.

“Then he said they should ‘cool it,’ but he realized he loved her, too,” said Levitz, adding that’s when the romantic relationship got underway.

She was then 16 years old.

He started to fold Neville into his family life, even bringing her on a family ski trip organized by his church.

In 2002 she would go to his family home for dinner.

“He said she needed friends,” said Levitz. “They later found out later she was pregnant…Then they brought her into the home … (and) into the family.”

Life in the intervening years wasn’t explained, however Levitz said that in the weeks and months preceding her murder, Thomson started showing jealous and possessive behaviour.

“He believed she was cheating on him with a colleague from work … with someone Neville had never met in person nor was she planning to,” said Levitz, noting that Neville worked from home in a job she was able to do online.

“He searched his computer for spying equipment and had come across correspondences with coworkers, including supposed boyfriend.”

In the investigation that followed, Levitz said that letters that Neville had written were found detailing what she was going through.

“They say the accused was mad at her for managing her email, she was afraid to check email because (she) didn’t know how he would respond, and she gave him access because she didn’t do anything wrong,” he said. “The accused looked at email and had been freaking out ever since.”

Neville wrote about how she was frustrated that Thomson didn’t trust her and that he made false allegations. He didn’t like that she had a job.

This jealousy issue was reiterated by Thomson in the years following Neville’s murder.

He told his former wife that Neville was cheating on him or was going to cheat on him with some other guy.

“‘You don’t know what I went through, it wasn’t fun,’” he’d said to her, Levitz told the court.

Thomson told her that the house they shared was messy, and when he tried to clean it up and she would yell at him.

Neville was also allegedly opening a lot of credit cards and spending freely.

Until recently, he’d never told people that he killed Neville. Only that he’d gone to get donuts, as per a request she’d made, and when he returned he found her dead.

He concocted a story for police in the immediate aftermath that he saw “a native male or a big Indian” running from the backyard of the home when he came back with the donuts. He claimed he ran in to check on the children, who were fine, then he went upstairs and found Neville lying on the floor.

RCMP composed a sketch at that time and distributed it to the media. A year later the sketch was withdrawn with no explanation.

“For the past five-and-a-half years, he not only deceived police but also family and other people,” said Levitz. “For the five-and-a-half years since Neville was murdered he maintained alibi that he was away from house when she was murdered.”

Thomson returns to court Jan. 24 for sentencing.

Jay Thompson pleads guilty to second degree murder in the 2013 death of Theresa Neville. More to come.